implement automatic ipv6 address finding

also pin to mac address

fixes #7

hardware/hetzner_ax51-nvme/network.sh

@@ -1,18 +1,24 @@
 #!/bin/bash -e
 
-address=$(ip address show dev eth0 scope global | grep -F 'inet ' | perl -pe 's#.*inet (.*?)/.*#$1#')
-gateway=$(ip route list dev eth0 default | perl -pe 's#.*via (.*) #$1#')
+default_routev4=$(ip route list | grep -F 'default')
 
-# $interface differs from the live system because of different naming schemes
-# see https://wiki.debian.org/NetworkInterfaceNames for more details
-interface='enp35s0'
+interface=$(echo "$default_routev4" | perl -pe 's#^.* dev (\w+) .*$#$1#')
+macaddress=$(ip address show dev "$interface" | grep -F 'link/ether' | perl -pe 's#^.*link/ether ([a-z0-9:]*) brd .+$#$1#')
+
+addresses=$(ip address show dev "$interface" scope global)
+
+gatewayv4=$(echo "$default_routev4" | perl -pe 's#^.* via ([\d.]+) .*$#$1#')
+addressv4=$(echo "$addresses" | grep -F 'inet ' | perl -pe 's#^.* inet ([\d.]+).*#$1#')
+
+addressv6=$(echo "$addresses" | grep -F 'inet6 ' | perl -pe 's#^.* inet6 ([a-z0-9:]+)::[a-z0-9]+.*$#$1#')
 
 
 echo "[Match]
-Name=$interface
+MACAddress=$macaddress
 
 [Network]
-Gateway=$gateway
+Gateway=$gatewayv4
+Gateway=fe80::1
 Address=116.202.199.132/32
 Address=116.202.199.133/32
 Address=116.202.199.134/32
@@ -27,5 +33,8 @@ Address=5.9.203.246/32
 Address=5.9.203.247/32
 
 [Address]
-Address=${address}/32
-Peer=${gateway}/32" > "/etc/systemd/network/${interface}.network"
+Address=${addressv4}/32
+Peer=${gatewayv4}/32
+
+[Address]
+Address=${addressv6}::1337/64" > "/etc/systemd/network/internet.network"